Ambulatory medical infusion pumps are a commercially successful and popular medical instrument. The pumps allow for the convenient continuous and calibrated delivery of a variety of medicines including but not limited to antibiotics, pain relieving drugs, and chemotherapy drugs.
The pumps have a fastener system that allows a supply tube to be removably attached to the pump. The supply tube can be installed on a cassette that has a soft pliable drug reservoir bag placed within a hard shell made from a rigid plastic such as poly-carbonate to protect the integrity of the bag. The supply tube has a soft section positioned within the pump assembly which is squeezed between the pump and the cassette pump plate to draw or pump the medicine through the supply tube.
The soft tube section is attached to microbore tubing that exits the pump assembly. The microbore tubing has a luer lock or similar connector attached to its distal end that allows connection to a intravenous infusion or subcutaneous delivery system. The microbore tubing resists any unintentional kinking or crimping thus assuring proper delivery of the drugs therethrough.
The pump plate of the pump cassette is permanently secured either by adhesive or sonic welding to the cassette shell to assure that the shell is not unintentionally removed from about the bag so that the bag does not become accidentally exposed and maintains its integrity against accidental puncture.
Often larger amounts of medicine are needed by the patient. Instead of numerous cassettes with a small bag in each cassette, a larger remote bag of medicine is used. The cassette that attaches to the pump includes only a soft supply tube that engages the pump, a microbore outlet tube that attaches to the patient, and a microbore inlet tube that attaches to the remote bag. The inlet tube and outlet tube have distal ends permanently attached to fittings such as luer locks. The fittings maintain the tube assembly permanently secured to the cassette. The microbore tubes are permanently connected to opposing ends of the supply tube. The cassette is constructed to permanently retain the supply tube in place. This cassette assembly is often referred to as a remote reservoir cassette or remote cassette.
When the medicine needs to be changed, one supply bag is easily disconnected from the pump cassette and another supply bag with a second medicine is conveniently attached to the pump cassette.
Because the supply tube has been in fluid contact with a patient, the used remote cassette may contain bodily fluids that passed up through the tubing from the patient. Thus, the tubing is considered medical waste and must be disposed of accordingly. Many principalities now have laws that forbid medical waste from being placed in landfills. The preferred disposal method is by incineration. For proper incineration, the cassette with both the spent tube and hard shell need to be incinerated at relatively high temperatures compared to regular incineration temperatures of other waste products. The higher temperatures are needed for the proper decomposition of certain chemotherapy drugs and for certain rigid plastics such as poly-carbonate. The cassette shell is incinerated with the reservoir bag, even through the cassette shell can be easily resterilized and capable of storing another tube for reuse with the pump.
The pumps are constructed for long durability. the pump thus can be used with many cassettes during its useful life over several years.
The increasing expense and difficulties of proper disposal of the cassette assembly necessitates that only the waste be disposed of and other parts be repaired and reused when possible and convenient. The reuse of the cassette shell can save much plastic and reduce the amount of unnecessary incineration and the unwanted particulates and gasses produced by incineration. What is needed is a method of removing the spent supply tube and fittings and reinstalling a new supply tube and fitting on the cassette shell.